Mild Postnatal Hydronephrosis Is Not Associated With Increased Vesicoureteral Reflux

Background: Antenatal hydronephrosis is known to be associated with vesicoureteral reflux (VUR). However, the incidence of VUR in postnatally diagnosed hydronephrosis is unknown. Hypothesis: The prevalence of VUR is increased in infants diagnosed with hydronephrosis on postnatal ultrasonography. Methods: Infants admitted to our NICU between January 1998 and September 2007 and diagnosed with hydronephrosis on postnatal ultrasonograpy were included. Results: One hundred thirty six infants were diagnosed with hydronephrosis by postnatal ultrasound and qualified for the study. Ninety two infants (67.7%) had grade I hydronephrosis, 34 infants grade II hydronephrosis (25%), 9 grade III hydronephrosis (6.6%) and one infant (0.7%) had grade IV hydronephrosis. Voiding cystourethrograms (VCUG) were performed on 90 infants (66.2%). Only 2 infants (2.2%) had VUR. Both of the infants who had VUR also had other associated major congenital anomalies. Conclusion: Mild postnatal hydronephrosis in our study population was not associated with an increased incidence of VUR.